Of the armor ceramics commercially available today, hot-pressed silicon carbides (SiCs) are very effective against a wide range of ballistic threats. Pressureless-sintered SiCs are attractive alternatives to hot-pressed variants for some particular applications based upon cost. The microstructural and mechanical property differences between hot-pressed and pressureless-sintered variants result in different damage mechanisms and/or damage kinetics which are qualitatively believed responsible for differences in their ballistic performances. Characterizing and quantifying the differences in microstructure, mechanical properties, and damage behavior is therefore important for building the connections between processing, microstructure, properties, and performance. Two commercially-available SiC variants, Saint Gobain Hexoloy (pressureless-sintered) and BAE Systems SiC-N (hot-pressed), were characterized and examined using instrumented Hertzian indentation in order to quantitatively and qualitatively compare their damage responses to very large localized stresses. Spherical diamond indenters with nominal diameters of 0.5 mm and 5.0 mm were used to explore both a quasi-plastic mode response and brittle mode response in these ceramics. Acoustic emission data was acquired during the indentation testing in an attempt to correlate loads with specific macrocrack-types. Optical and electron micrographs of the samples will be shown.
Instrumented hertzian indentation study of two commerical silicon carbides
2009
7 Seiten, 11 Quellen
Conference paper
English
Anwendung in der Wehrtechnik , Ballistik , Drucklossintern , Elektronenmikroskopie , Härteeindruck , Heißpressen , Hertz-Kegelbruch , Makroriss , Mikrostruktur , militärische Ausrüstung , optische Mikroskopie , Panzerblech , plastische Verformung , Schädigungsmechanismus , Schallemissionsprüfung , Schlageindringtiefeprüfung , Siliciumcarbid , Sprödigkeit , Verfahrensvergleich , Werkstoffverschleiß
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